This invention relates to a mechanism of a time detecting device for a clock having an electric alarm signaling device which is actuated at the predetermined alarm signaling time.
The essential mechanism of the conventional time detecting device for an alarm clock is a drop-in type mechanism constituted of a hole and projection provided for a time detecting wheel and a corresponding time wheel rotating at a fixed rate, respectively.
This mechanism has a disadvantage that the alarm signaling time setting knob or the time indication adjusting knob can be rotated only in one direction in alarm signaling time setting or in time indication adjusting because the wall of the hole and the side face of the projection are shaped vertically straight with each other so as to make the projection drop into the hole instantaneously to attain accurate time detection. A further disadvantage of this conventional mechanism is that the electromechanical transducer is undesirably loaded when the projection escapes out of the hole along the inclined wall of the hole in accordance with rotation of the wheels.